Crosslinkable NLO dendrimers based on azobenzene-type chromophores were synthesized by a Diels-Alder reaction. Their thermal and optical properties were investigated before and after poling at a high temperature. We found that the dendrimers retained good thermal stability up to 260 degrees C after curing at 130 degrees C for 10 min based on thermal analysis. Through in-situ poling and curing processes, the highest NLO activity of the dendrimers was d33 = 1.7 x 10(-6) esu at 1064 nm, which was determined by a Maker fringe experiment.
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http://dx.doi.org/10.1166/jnn.2012.5357 | DOI Listing |
J Org Chem
January 2025
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China.
The asymmetric total syntheses of sarglamides A, C, and E in concise and protecting group free fashion is disclosed. Key steps involve an -selective Diels-Alder reaction to construct the bicyclo[2.2.
View Article and Find Full Text PDFBioorg Chem
January 2025
Sakarya University, Faculty of Arts and Sciences, Chemistry Department, 54050, Sakarya, Turkey. Electronic address:
In this study, Diels-Alder reaction was performed to sulfolene and endo/exo-diacetate compounds. After a series of reactions, new conduritol A and F analogs containing oxo-bridge and naphthalene rings in their structures were synthesized. To the starting compound, bromination, elimination, singlet oxygen reaction, acetylation, selective oxidation with osmium tetroxide (OsO), and m-chloroperbenzoic acid (m-CPBA), re-acetylation, and finally hydrolysis of the compounds by NH(g)/MeOH reactions were carried out.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
Here, we report the enantioselective total syntheses of four diepoxy--kaurane diterpenoids including (-)-Macrocalin B, (-)-Acetyl-macrocalin B, and (-)-Isoadenolin A and the revised structure of (-)-Phyllostacin I, which hinges on the strategic design of a regioselective and stereospecific trapping of a highly reactive [3.2.1]-bridgehead enone intermediate via a tethered intramolecular Diels-Alder reaction.
View Article and Find Full Text PDFMolecules
November 2024
Catalyse Organométallique, Synthèse Organique et Santé (COSyS), Institut de Chimie (UMR-CNRS 7177), Université de Strasbourg, 67000 Strasbourg, France.
Due to the importance of biaryls as natural products, drugs, agrochemicals, dyes, or organic electronic materials, a green alternative biaryl synthesis has been developed based on easy-to-prepare and cheap copper(I)-exchanged zeolite catalysts. Cu-USY proved to efficiently catalyze the direct homocoupling of either phenols or aryl boronic acids under simple and practical conditions. The Cu-USY-catalyzed oxidative homocoupling of phenols could conveniently be performed under air either in warm methanol or water with good to high yields.
View Article and Find Full Text PDFEur J Med Chem
February 2025
Laboratory of Medicinal and Organic Chemistry, Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Hněvotínská 1333/5, 779 00, Olomouc, Czech Republic. Electronic address:
Starting from benzyl 30-oxobetulinate and 30-oxobetulin diacetate, substituted dienes were synthesized and subjected to Diels-Alder reaction, yielding a variety of triterpenoid phthalates, phthalimides, and related derivatives. A total of 55 new compounds were prepared and tested for in vitro cytotoxic activity against eight cancer cell lines and two non-cancerous cell lines. Four compounds with IC values of 5 μM or lower were selected for further investigation.
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